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PCs, servers, switches, routers, broadband modems, KVM
switches, and other computer equipment are all subject to electrical damage.
From improper site wiring to lightning strikes, a wide variety of electrical
issues threaten systems and peripherals constantly. Review
these 10 items to ensure that you’ve taken necessary precautions to help
protect against data loss and equipment damage.
#1: Verify electricity levels
Most computer equipment is designed to use 120 volts of AC
power supplied at 60 Hertz. Electrical current provided by a local utility or
throughout a site or facility can vary from that standard, however, sometimes
When deploying new systems, and as facilities are expanded
and adjoining sites grow, be sure the local power grid continues providing
proper electrical baselines. Both sags and surges adversely affect PC and
server electrical components and can lead to subsequent failures and data loss.
Use a multimeter to reveal the voltage an AC power outlet
provides to systems and equipment (Figure A). If baselines vary by two
percent or less, invest in electrical conditioning equipment, such as an uninterruptible
power supply (UPS). If baselines vary by three percent or more, contact the
local utility, a licensed electrical contractor, or facilities management to explore
and correct the errors.
|A multimeter reveals a UPS power outlet provides 121.5 volts of AC electricity.|
#2: Confirm that supply circuits are grounded properly
Surge protectors and UPS devices can’t properly safeguard
the sensitive hardware they’re designed to protect if the electrical outlets
they’re plugged into aren’t properly grounded. Ground wiring is responsible for
diverting most power surges. When ground wiring is compromised, surges don’t
have an effective suppression path. Expensive servers, PCs, and network
equipment can subsequently suffer significant damage.
Information technology professionals typically aren’t
responsible for a facility’s wiring quality, but as they’re responsible for
maintaining the computer systems and networks powered by the facility’s
electrical supply, IT pros have an interest in ensuring electrical outlets and
power supplies are properly grounded.
Many UPS and surge protector models will light a warning
lamp if the outlet into which they’re plugged isn’t properly grounded. Most
do-it-yourself and hardware stores also sell inexpensive circuit testers (Figure
B) that are simply plugged into outlets to confirm that circuits are
|A simple circuit tester can quickly confirm that power outlets are grounded
Whenever deploying new equipment, be sure to first test the
circuit. When using surge protectors or UPS devices that feature improper-grounding
alarms, also verify that the alarm light isn’t lit.
#3: Don’t overload circuits
Remember the Christmas
Story scene in which Ralphie’s dad blows a fuse connecting too many
electrical plugs into a single outlet? In the popular holiday movie, a string
of decorative lights is to blame, but too many desktop computers, servers, and
network devices connected to a single circuit
can easily overpower the electrical supply. Notice I didn’t say too many
desktop computers, servers, and network devices connected to a single outlet.
Splitting outlets (using power strips, surge protectors, and
UPS devices), of course, does nothing but multiply the power demands placed
upon the circuit to which those outlets are connected. Placing excessive
demands upon a circuit can result in intermittent power failures, wide
variations in available electricity, and even fire hazards as overworked
circuits exceed safe operating ranges.
As CPU speeds and capacities and video card capabilities,
among other elements, have increased, server and PC power requirements have
grown as well. Carefully research your server room or office’s power
requirements to make sure the site’s electricity requirements are sufficient.
Several resources are available for helping estimate
appropriate power levels. Check out these sources for more information:
Total Power Requirements for Data Centers (APC White Paper)
the Data Center Efficiently (Hewlett-Packard White Paper)
- System Power and
Cooling Requirements (Sun Microsystems Book Chapter)
#4: Use a UPS/surge protector
Avoid deploying unprotected power strips, which do nothing
to protect connected equipment from sags, surges, and lightning strikes. Deploy
surge protectors and UPS devices instead.
Connect all sensitive electronic equipment to UPS or surge
protection devices. Remember that a laser printer’s fusers generate strong
bursts of electrical consumption that can damage UPS units.
Mobile systems pose a particular challenge. Ensure that all
traveling employees carry and use effective surge protectors when traveling
#5: Properly calculate UPS/surge protector capacity
Just as electrical circuits can easily be overwhelmed, so
too can a UPS device’s power capacity be exceeded. Carefully calculate the
power demands for the systems attached to a UPS device to ensure that the UPS can
power the connected equipment.
Most UPS manufacturers provide interactive calculators you
can use to estimate the volts-amperes and watts required to power your systems.
Use these links for more information:
Power Conversion Corp.’s product selection wizards
product selection wizards
Lite’s product selectors
When selecting surge protectors, purchase models featuring a
sufficient number of protected outlets. A five-outlet surge protector may cover
five devices, but it does no good if additional unprotected outlets must be
utilized for other systems or peripherals.
Also ensure the surge protector selected includes lightning
protection. Without protection from common thunderstorms, a surge protector can
prove useless in safeguarding sensitive computer equipment from electrical
spikes, resulting in failed hardware and corrupt and lost data.
#6: Replace damaged or faulty UPS/surge protectors
When a surge protector or UPS sustains a significant
electrical surge, such as occurs with a lightning strike, the device’s internal
electronics can fail. If warning lamps light, outlets stop operating, or
batteries fail, replace the damaged component or the entire UPS or surge
protection device. You should do this even if the unit’s telecommunications
protective mechanism is the only component that fails.
Although it’s tempting to continue using a UPS with only a
single dead outlet or port, the fact the device sustained an electrical charge
sufficient to damage components indicates that other damage may have occurred.
Such damage could prevent the UPS or surge protector from properly protecting
connected equipment, thus necessitating the device’s replacement.
#7: Protect telecommunications links
Always make sure that servers, PCs, and network equipment
receive protection from electrical spikes that can travel telecommunications
links. Lightning strikes frequently discharge via cable modem, DSL, and
telephone lines. The discharge isn’t pretty, as everything from network
interface cards to motherboards can be destroyed.
When purchasing UPS and surge protection devices, look for
models that protect connected equipment from lightning strikes entering the
network via data lines. Then, when deploying the UPS or surge protector, be
sure to connect the data line to the protective device’s input. Connect a
corresponding RJ-11 or RJ-45 cable to the device’s protected output to guard
against lightning damage on your network.
#8: Test power supplies
Delicate electronic components within a computer, such as
hard disk motors, memory, video cards, and motherboards, are sensitive to even
minor fluctuations in a system’s electrical supply. Even if circuits have been
tested, proper grounding has been verified, and UPS or surge protectors are in
place, a system’s wayward power supply can inflict electrical damage on a PC or
Power supplies are a frequent cause of system reboots and
failures. I’ve seen a power supply (on a system attached only to a power strip)
continually reboot a machine while in the process of overheating. Thick, acrid
white smoke poured from the malfunctioning power supply while the system kept
repeating vain attempts to restart.
Whenever you encounter unexplained or intermittent reboots
and other flaky behavior, check the power supply’s electrical output to ensure
it’s working properly. Use either a multimeter, set to read the proper
voltages, or a tool specifically designed to test a power supply’s output (Figure
|Devices such as this Vastech ATX 2.0 Power Supply Tester make testing power
Malfunctioning power supplies should be replaced immediately
to protect a system’s components from electrical damage and potential fire
hazards. If a power supply has been distributing excessive electrical power to
a system, it’s not a bad idea to test the motherboard, CPU, memory, and other
components using a POST card to make sure that no additional repairs are
#9: Maintain proper operating temperatures
Temperature is a well-known and well-documented enemy of
network switches, firewalls, PCs, servers, and other equipment. High
temperatures can adversely affect power supplies, potentially causing damage to
a system’s internal components. High temperatures can also prevent a UPS
device’s internal electronics from working properly, thereby leaving connected
systems and equipment at risk.
Protect against electrical damage resulting from overheating
by ensuring that systems receive proper cooling. Keep all vents and fan outlets
free of debris, boxes, files, folders, and other furniture. When performing
routine system maintenance, verify that PC and server exhaust fans are working
properly and are unobstructed.
I’ve encountered situations in which a PC’s exhaust fans
were blocked by documentation placed inside the system (to prevent the discs
and license numbers from becoming separated from the unit or being lost). A
good idea in theory, but the resultant ventilation loss prompted the hard disk to
fail as a result of its baking in the heat generated by its own electrical
Take steps to ensure that UPS devices also receive ample
room to breathe. Don’t stack boxes, retired PCs, or other equipment alongside
UPSes, either in server rooms or in cubicles.
Electricity use consistently generates heat, and that heat
must be dissipated properly or damage and potential data loss will result. It
sounds simple, but take a quick walk through any office environment and you’ll
almost always find at least one UPS buried by boxes, files, or other office
#10: Maintain proper insurance
You can take numerous steps to prevent electrical damage to
computers, servers, and other computing equipment, but sometimes your best
efforts simply aren’t sufficient. I’ve seen clients lose motherboards, NICs,
hard disks, and more due to lightning strikes. Some of the damaged equipment
was even connected to UPS and surge protectors.
Despite precautions, equipment can still end up being lost
to electrical damage resulting from surges, lightning, and other disturbances.
Business owners, even those with small operations, should make sure that
insurance policies include riders or passages expressly covering computers and
associated equipment. IT professionals employed by larger organizations should
also work with their CTOs to properly maintain documentation required by the
Review your organization’s property and casualty insurance
homeowner’s policies. Regardless of organization size, you should record the model
numbers, serial numbers, and purchase prices of all equipment. Also, collect photographs
of all computer and related items. Both the insurance policies and the supporting
documentation should be securely stored off site. If a devastating electrical
crisis does occur, having proper insurance and associated documentation can
help your organization recover much more quickly and efficiently.